The Most Intense 30 Minutes Ever: I Tried Les Mills’ New Grit Series Class

Is it just me, or do gym classes seem to be getting shorter and more efficient all the time? Sure, there's still the occasional 90-minute yoga class, but fitness clubs these days know that we're in a rush--and thanks to the science of high-intensity interval training (HIIT), they've got ways to get us real results in less time than ever.

Take the new New Zealand-based Les Mills Grit Series, rolling out at gyms around the country this month: It calls itself "the most intense 30 minutes your body will ever experience," and I have to say they could be right. Check out their video promo to see what I mean!

Grit Series classes focus on cardio, strength training, and plyometrics–those explosive power moves like high-knee jumps and burpees. There are three versions of the class, each one focusing on one aspect a little more than the others (I sampled the Cardio class, and the Strength class is highlighted above), but every session does make sure to incorporate all three pillars. My instructor, the adorably-accented Les Mills, Jr. himself, explained that we’d be doing bursts of 110% effort, followed by short periods of rest and recovery–hence the “high-intensity” and “intervals” parts of HIIT.

The brand’s research show that their program works, too: When they had Penn State researchers track two groups of exercisers on professionally-designed workout plans, the group that swapped 60 minutes of cardio for two 30-minute Grit Series sessions lost more than twice as much body fat and saw a four-fold decrease in their triglycerides, one part of total cholesterol.

What can you expect in a Grit Series class? Non-stop action; even the recovery periods include some type of movement. Lots of squats, jumps, pushups and ups-and-downs from horizontal to vertical–my quads were sore on the stairs for days. Some classes use weights, like Les Mills’ adjustable SmartBar barbell, while others don’t require any special equipment. You’ll push your heart rate to the max, and you’ll sweat, a lot. And while you can always skip between the Strength, Cardio and Plyo classes to get some variety, they’re all updated every three months to give your body fresh new challenges.

Grit Series is (or will soon be) at select 24-Hour Fitness and Bally Total Fitness locations, and at lots of independent gyms around the country; you can find a class near you here.

Are you a fan of HIIT? Tweet us your experience with Grit Series–or other kick-ass high-intensity classes–at @amandaemac and @SELFmagazine.